...a filter bag over the filter intake so the fry don't get sucked up...
will not tend to keep the fry from getting pulled against the bag as the bag will tend to collapse against the openings in the seive. I have checked various methods of DIY filter intake fry protectors and I came up with this idea. The basic principle is to increase the surface area of the intake and thereby decrease the water flow rate so the fry can avoid being sucked against the intake and rendered immobile. Sure... good parents will rescue them quite often... but there's an easy better way. One of the designs I looked at required cutting lengthwise holes/slots in a section of PVC and wrapping it with women's nylons or screening of some sort and epoxying it in place...
My solution is quite simple, structurally sound, and tremendously increases the intake surface area. Why measure and cut holes in PVC pipe and then measure and cut the screening to fit the pipe section?
Simply use stainless steel mesh screening as your pipe!!!! roll it up to your desired diameter and epoxy PVC end caps and fittings on it to complete the perfect filter guard.
I used stainless steel mesh ordered from Amazon to perfectly suit my needs.
Copy and paste in your Amazon search queue to find the same item:
ASC Stainless Steel Mesh 304,#20 .016 Wire,Cloth,Screen,Woven wire 12"X12"
This mesh has 20x20 holes per square inch and is near perfect size to protect the smallest of free swimming fry
The end cap/adapter shown to the right is for 2" to .75" threaded reduction which near perfectly fits 16mm intake pipe. I also epoxied a piece of foam over the adapter opening an have a hole in it just big enough to slide the intake pipe through before assembling the entirety (in tank) with the original filter strainer fully enclosed and centered within.
It's not the prettiest thing in the world but it is totally 100% functional.
Pieces needed:
12x12 stainless mesh approx $14 w/ prime account (free shipping)
2" PVC End Cap$2.75 ish
2" PVC Coupling $3 ish
2" to your size pipe reducer $3.75 ish
Marine grade JB Weld 2 Part Epoxy (15 hour cure)
(which gave me plenty of working time to accommodate my handicap).
Bunch of twelve inch cable zip ties for assembly or whatever you need to hold it tight against itself while the epoxy cures (a simple tight spiral of fishing line would also work well).
It is shown upside down in the photo (epoxy still setting on the coupler which the adapter to the right simply slides into for a snug fit after the intake sieve is removed from the intake pipe and this adapter slid in place - then reattach the intake sieve and then place the protector right side up and attach to the adapter and done!!!
Cleaning is a snap!... just brush it off as needed for the most part and siphon the particulate away during a water change.
The only thing not shown in the pic is the foam cap, but I think you get the idea.
Tank depth is 21 inches
Overall length filter guard is 17 inches with adapter, coupling, screening. and end cap and 1" of foam to seal the pipe opening at the top.
It's perfect! Easily installed and uninstalled and will last practically forever!
My flow rate is 325 gallons per hour and the fry have yet to get stuck against it.
